Alanine mutation of the targeting subunit of the myosin phosphatase, MYPT1 at threonine 696 reduces cGMP responsiveness of mouse femoral arteries.

Autor: Lubomirov LT; Institute of Physiology, Brandenburg Medical School Theodor Fontane, Germany; Institute of Vegetative Physiology, Center of Physiology, University of Cologne, Germany; Vascular Biology Research Group (RenEVA), Research Institute, Medical University-Varna, Varna, Bulgaria; Institute of Physiology and Pathophysiology, Faculty of Health - School of Medicine, Biomedical Center for Education and Research (ZBAF), Witten/Herdecke University, Witten, Germany; Research Cluster, Molecular Mechanisms of Cardiovascular Diseases, Brandenburg Medical School Theodor Fontane, Neuruppin, Germany. Electronic address: lubomir.lubomirov@mhb-fontane.de., Weber G; Institute of Physiology, Brandenburg Medical School Theodor Fontane, Germany., Schroeter M; Institute of Vegetative Physiology, Center of Physiology, University of Cologne, Germany., Metzler D; Institute of Vegetative Physiology, Center of Physiology, University of Cologne, Germany., Bust M; Institute of Vegetative Physiology, Center of Physiology, University of Cologne, Germany., Korotkova T; Institute of Vegetative Physiology, Center of Physiology, University of Cologne, Germany., Hescheler J; Institute of Neurophysiology, Center of Physiology, University of Cologne, Germany., Todorov VT; Institute of Physiology and Pathophysiology, Faculty of Health - School of Medicine, Biomedical Center for Education and Research (ZBAF), Witten/Herdecke University, Witten, Germany; Experimental Nephrology and Division of Nephrology, Department of Internal Medicine III, University Hospital and Medical Faculty Carl Gustav Carus, Technische Universität Dresden, 01307, Dresden, Germany., Pfitzer G; Institute of Vegetative Physiology, Center of Physiology, University of Cologne, Germany., Grisk O; Institute of Physiology, Brandenburg Medical School Theodor Fontane, Germany; Research Cluster, Molecular Mechanisms of Cardiovascular Diseases, Brandenburg Medical School Theodor Fontane, Neuruppin, Germany.
Jazyk: angličtina
Zdroj: European journal of pharmacology [Eur J Pharmacol] 2025 Jan 05; Vol. 986, pp. 177133. Date of Electronic Publication: 2024 Nov 17.
DOI: 10.1016/j.ejphar.2024.177133
Abstrakt: The femoral artery (FA) is the largest vessel in the hindlimb circulation and its proper tone regulation ensures adequate blood supply to muscle tissue. We investigated whether an alanine mutation of the targeting subunit of myosin-light-chain-phosphatase (MLCP), MYPT1, at threonine 696 (MYPT1-T696A/+), decisive for enzyme acivity, affects the responsiveness of young and old FAs (y-FAs and o-FAs) to activation of nitric-oxide/soluble-guanylate-cyclase/protein-kinase-G cascade (NO/sGC/PKG). Contractile responses of the vessels were measured by wire myography. Phosphorylation of the regulatory myosin-light-chain at serine 19 (MLC 20 -S19), the myosin-light-chain-phosphatase targeting subunit, MYPT1-T696, the PKG-sensitive site of MYPT1 at S695 (MYPT1-S695) and S668 (MYPT1-S668), and the regulatory phosphorylation of eNOS at S1177 (eNOS-S1177) were determined in arterial homogenates by Western blot. In FAs of all ages, the MYPT1-T696A-mutation did not alter vessel diameter and the contractile reactivity to the thromboxaneA 2 -analogue, U46619 and the RhoA kinase inhibitor, Y27632. In contrast, the mutation T696 into alanine attenuated the relaxing effect of exogenous NO (DEA-NONOate) in y-FAs. The effect of a direct sGC activation by cinaciguat was also attenuated in both age groups of MYPT1-T696A/+, but strongly in o-FA. The MYPT1-T696A-mutation also attenuated acetylcholine-induced relaxation, but only in o-FAs. Similary, the alanine mutation attenuated the acetylcholine effect on MLC 20 -S19- and MYPT1-T696 only in WT o-FAs. Interestingly, neither eNOS-S1177 nor the phosphorylation of the PKG phosphospecific sites, MYPT1-S695 and MYPT1-S668 were altered by MYPT1-T696A-mutation or aging. These findings suggest that the alanine mutation of MYPT1-T696 reduces the ability of the NO/cGMP/PKG-system to relax FAs in aging.
Competing Interests: Declaration of competing interest Hereby I declare in relation to the following Manuscript entitled “Alanine mutation of the targeting subunit of the myosin phosphatase, MYPT1 at threonine 696 reduces cGMP responsiveness of mouse femoral arteries” no potential conflicts of interests.
(Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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